properties config throw error:Cannot read property 'currentLanguageCode' of undefined

[SnailOfLife]

properties config throw error can't save when '=' right is null,even if the line is commented

Uncaught TypeError: Cannot read property 'currentLanguageCode' of undefined
    at main.js:38
    at main.js:78
    at Array.<anonymous> (main.js:78)
    at main.js:78
    at r (main.js:33)
    at e (main.js:33)
    at a (main.js:78)
    at t.value (main.js:38)
    at main.js:78
    at e (main.js:33)

environment

version 1.3.0